Key air pollution benchmark drops near Port of Los Angeles

Data from four air quality monitoring stations at and near the Port of Los Angeles show concentrations of a key type of pollutant have fallen to their lowest levels since the port began tracking them in 2005, officials said Thursday.

The data measures elemental carbon, an indicator of diesel particulate matter, which is produced by the combustion of diesel fuel. In Wilmington, elemental carbon levels have fallen 72 percent compared to 2006, the first full year of monitoring, according to port records. In San Pedro, the drop was 61 percent, port records show. Pollution levels at both places also dropped considerably compared to 2011. Real-time pollutants data can be monitored on the Web at http://caap.airsis.com/

Jessica Lass, press secretary for the environmental group Natural Resources Defense Council, commended the port for its advances but cautioned that particulate levels must continue to fall. She said the NRDC opposes a proposed new railyard at the port on the grounds that it will likely increase pollution for areas near the facility.

"Reducing diesel air pollution is a commendable goal and a significant change from levels seen a decade ago," Lass said in an email. "However, there's more work to be done to ensure these levels remain low as the port considers expansion projects that could harm local communities."